Slab barker having scraper



Aug. 19, 1958 J. GYLLENBERG 2,848,022

SLAB BARKER HAVING SCRAPER Filed Nov. 9, 1956 Tam l IINVENTOR. JOHN L. GYLLENBERG FIG. 2 I M9454 ATTORNEYS SLAB BARKER HAVDJG SCRAPER John L. Gyllenberg, Baker, Oreg, assignor to Anthony Brandenthaler, Baker, Greg.

Application November 9, 1956, Serial No. 621,229

2 Claims. (Cl. 144-2tl8) This invention relates to slab barkers and particularly to slab barkers in which the bark is removed by mechanical means rather than hydraulic means. The present application has certain parts in common with my prior copending application entitled Slab Barking Machine, Having Swingably Mounted and Pncumatically Biased Brush and Rotary Cutters, Serial No. 528,182, filed August 15, 1955, now Patent 2,794,465, granted June 4, 1957, and my prior copending application entitled Log Barking Machine Having Brush Means, Serial No. 578,448, filed April 16, 1956.

It has been found that the bark may be removed from slabs of all types by employing rotary barking tools which are power driven at rapid speeds relative to the slab being debarked. These tools are mounted adjacent the conveyor which conveys the slab through the machine to enable the tools to remove bark from a slab. However, it is necessary to avoid contact between the rapidly rotating tools and the conveyor to prevent damage to the machine and injury to the operators.

Thus, it has been conventional practice to provide a substantial space between the rotary tools and the conveyor to avoid any possibility of contact therewith. This means that not all of the bark is removed from a slab, particularly from thin slabs or from the thin ends of ordinary slabs, because thin slab portions merely slip between the tools and the conveyor.

Another problem encountered in slab barkers is that With slabs having very tough bark, it is difiicult to drive the slabs through the machine because the driving force required is so great that the slab slips relative to the conveyor. I have discovered that a conveyor equipped with driving spikes is capable of successfully driving a slab through the machine but the danger of contact between such spikes and the rapidly rotating barking tools has heretofore discouraged the use of such spikes.

A main object of the present invention is to provide a slab barker which is capable of removing the bark from thin slabs or ordinary slabs having thin ends and which employs rotary barking tools and driving spikes for driving the slabs through the machine, which machine is so constructed that there is no possibility of contact between the tools and spikes.

A more specific object of the invention is to provide 'a slab barker in which the rotary barking tools are laterally spaced to clear the row of driving spikes, and a relatively stationary scraper member is arranged behind the rotary tool to remove any strip of bark that might be left because of the space between the tools.

Various other objects of the present invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

Fig. 1 is a side elevation of a slab barker of the invention, parts being broken away for convenience in illustration;

Fig. 2 is a fragmentary vertical section on an enlarged scale taken along line 22 of Fig. 1 showing details of the scraper member;

2,848,022 Patented Aug. 19, 1958 Fig. 3 is a schematic view taken generally in the same direction in which Fig. 2 is taken, and showing the relationship of the scraper member and the primary barking tools; and

Fig. 4 is a fragmentary elevation taken in the direction of the arrows 4-4 in Fig. 1 showing more clearly the construction of the scraper member.

The slab barker shown is in many respects similar to the barker disclosed in my prior copending applications, heretofore identified and thus only belief reference will be made to parts that are in common with such applications. Referring to Fig. 1, in general, the slab barker shown includes a chain conveyor 9 for conveying a slab from right to left through the machine and past a pair of primary barking tools 11, then past a scraper member 13, then past a pair of secondary barking tools 15 and then past a brush 17. Three rotary feed wheels 19 cooperate with the conveyor 9 in feeding the slabs through the machine and also in maintaining the slab down against the upper reach of the conveyor.

More particularly, the machine includes a frame including a pair of side plates 21 and 23 mounted on a pair of skids 25 and connected by various cross members unnecessary to describe. A table 27 is provided between the plates 21 and 23 at one end thereof to support slabs while they are being shoved onto the upper reach of the chain conveyor 9. The chain conveyor is trained around a pair of sprockets 31 and 33 rotatably mounted on the frame, the sprocket 31 being driven by a motor 35 through a chain 37. A speed-reduction unit, not shown, of suitable form is arranged between the motor and sprocket so that the conveyor '9 travels at a rate which is relatively slow as compared to the rate of rotation of the log-barking tools 11 and 15. The feed wheels are also driven at a relatively slow speed from the motor 35 by means not shown.

The upper reach of the conveyor 9 rides in a channelshaped guide 41, as best shown in Fig. 2, which is supported by a pair of I beams 43 which form part of the frame of the machine. Secured to the alternate lengths of the conveyor along the length thereof are a plurality of upstanding feed elements 45 having serrated upper edges. More in particular, the upper edge of each feed element includes a central tooth 47 and two flanking teeth 48 of lesser height than the central tooth. Each central tooth is provided with an upstanding spike 49 for projecting into the fiat woody bottom surface of a slab for the purpose of driving a slab through the machine. The spikes project upwardly farther than any other portions of the upper reach of the conveyor.

Each of the primary barking tools 11 is mounted for independent movement toward and away from the upper reach of conveyor 5 by a parallel linkage which is similar to that shown in my copending applications. The linkage includes arms 61, 63 and 65, arms 61 and 65 being pivotally connected together whereas arms 65 and 63 are pivoted at their righthand ends on the frame of the machine. As is shown in Fig. 3, each of the tools 11 is mounted in cantilever fashion on its arms 61 and 63by a shaft 67 journaled in the arms.

It is pointed out that when thin slabs or normal slabs having thin ends are to be barked, the tools 11 must closely approach the conveyor chain 9 in order to remove the bark from the slab. in order to permit this without danger of engagement between the spikes 49 and the tools 11, the opposed inner faces '71 of the barking tools 11 are laterally spaced by a distance just suificient to clear the row of spikes 4-9 provided by the conveyor 9. In the present machine, the lower surfaces of the tools may move downwardly to a level even with or slightly below the tips of the spikes 49 to achieve effective barking of thin slabs or thin ends of normal slabs. Suitable ad- 3 justable stops, not shown, are provided for limiting downward movement of the tools relative to the conveyor.

The tools 11 are driven by chains 73, 75 and 77 from the motor 35. The direction of rotation of the tools may be clockwise or counter-clockwise, preferably clockwise, as the parts are shown in Fig. l, but in any event the tools are rapidly driven relative to a slab to remove the bark therefrom. A pneumatic piston-and-cylinder unit 81 is provided for yieldingly urging the tools 11 downwardly into engagement with a slab.

The scraper member 13 comprises a vertical blade, as is best shown in Figs. 1, 2 and 4, which is provided at its upper end with a hinge including knuckles 82 on the upper end of the blade receiving a hinge pin 83 which passes through knuckles 84 on a hinge leaf 86 secured to a transverse plate 85 which connects the side plates 21 and 23 of the machine. The scraper member has a curved or slightly hook-shaped lower edge 87 for engaging the bark in a tangential direction relative to the surface of the slab to effect a shearing action on the bark to remove the same. Referring to Figs. 2 and 3, the scraper member 13 is symmetrically disposed relative to the conveyor 9 and tools 11 so as to remove bark which might be left because of the space between the tools 11. From Fig. 2 it is apparent that the lower edge of the scraper is concave as shown at 90 for conformity to the contour of the slab.

Since the scraper member is relatively stationary with respect to the frame of the machine, it may be positioned closer to the conveyor 9 than the tools 11, because accidental engagement between the relatively stationary scraper member and the slow moving conveyor will not damage the machine nor endanger the operators as would be the case were the rapidly rota-ting power-driven tools 11 to engage the conveyor.

The scraper member is yieldingly urged by a pneumatic piston and cylinder unit 91 in a direction opposite the direction of travel of the upper reach of the conveyor 9 for pressing the lower edge of the scraper member into engagement with the bark-covered side of a slab.

The pneumatic piston-and-cylinder unit 91 is mounted on a bracket 93 secured to the plate 85 and to the gear housing 97. The gear housing is clearly shown in my prior copending application, Serial No. 528,182, and need not be here described. The purpose of the gear housing is to transmit power from the chain 77 to the secondary barking tools 15 by way of shafts 99 which are shown in Fig. 2 and which project from the housing. Referring to Fig. 1, the tools 15 are mounted by arms 101 on the shafts 99.

The feed wheels 19 are mounted for movement toward and away from the upper reach of the conveyor 9 and are suitably driven from the motor 35 in the manner disclosed in my prior copending applications, not necesasry here to describe. The brush 17 is mounted and driven in the manner described in my copending application, Serial No. 578,448, and further description of the brush is unnecessary.

With the machine of the present invention, the bark may be more readily removed from slabs than with prior barkers, particularly, the bark from thin slabs or normal slabs having thin ends because the tools may have continuous contact with thin portions of slabs. It is pointed out that the relatively stationary scraper blade is capable of removing any bark which might be left between the tools because such grip is without lateral support. In other words, were the scraper member pressed against the bark of a slab in its completely unbarked condition, it is extremely doubtful whether any effective bark removal would be accomplished. Thus it is the particular combination of the power-driven, rotary barking tools and the relatively stationary scraper blade and the row of driving spikes which makes the present machine fully operable.

Having described the invention in what is considered to be the preferred embodiment thereof, it is desired that it be understood that the invention is not to be limited other than by the provisions of the following claims.

I claim:

1. In a slab barker, a frame, a conveyor movably supported on said frame for conveying a slab in lengthwise fashion along a predetermined horizontal path with its bark-covered side uppermost, said conveyor having driving spikes for engaging the flat, woody bottom surface of a slab, said driving spikes projecting upwardly farther than any of the other portions of said conveyor, bark-removing means above said path for removing bark from such slab, said bark-removing means including a pair of rotary barking tools mounted for vertical movement toward and away from said path, said barking tools being symmetrically disposed relative to said conveyor and said spikes, power means for rapidly rotating said tools at a rate many times that of the rate of travel of said conveyor, said barking tools having the inner faces thereof lateraly spaced from one another a distance just to clear said spikes so as to prevent engagement between said rapidly rotating barking tools and said spikes, a vertical scraper member spaced from said tools in the direction of travel of said conveyor, said scraper member being generally stationary relative to said frame but being pivotally mounted at its upper end for limited pivotal movement about a horizontal transverse axis, said scraper memher being symmetrically disposed relative to such tools and conveyor so that said scraper member assumes a position above said spikes, and pneumatic means yieldingly urging said scraper member in a direction opposite the direction of travel of a slab to cause said member to yieldingly engage the central portion of a slab and remove any bark which might be left because of the space betwen said tools, said pneumatic means yielding upon accidental engagement between said scraper member and said spikes to prevent damage to said spikes or scraper member and said pneumatic means being yieldable upon engagement between said scraper member and a nonremovable portion of a slab so as to prevent damage to said scraper member and the spikes driving such slab.

2. In a slab barker, a frame, a conveyor movably supported on said frame for conveying a slab in lengthwise fashion along a predetermined horizontal path with its bark-covered side uppermost, said conveyor having a row of driving spikes for engaging the fiat, woody bottom surface of a slab, said driving spikes projecting upwardly farther than any of the other portions of said conveyor, bark-removing means above said path for removing bark from such slab, said bark-removing means including a pair of rotary barking tools mounted for vertical movement toward and away from said path, said barking tools being symmetrically disposed relative to said conveyor and said row of spikes, power means for rapidly rotating said tools at a rate many times that of the rate of travel of said conveyor, said barking tools having the inner faces thereof laterally spaced from one another a distance just to clear said row of spikes so as to prevent engagement between said rapidly rotating barking tools and said spikes, a vertical scraper member spaced from said tools in the direction of travel of said conveyor, said scraper member being generally stationary relative to said frame but being pivotally mounted at its upper end for limited pivotal movement about a horizontal transverse axis, said scraper member being symmetrically disposed relative to such tools and conveyor so that said scraper member assumes a position above said row of spikes, and pneumatic means yieldingly urging said scraper member in a direction opposite the direction of travel of a slab to cause said member to yieldingly engage the central portion of a slab and remove any bark which might be left because of the space between said tools, said pneumatic means yielding upon accidental en- 5 gagement between said scraper member and said spikes to prevent damage to said spikes or scraper member, said scraper member having a lower end portion which is curved in a direction parallel to said conveyor and op posite the direction of travel of the upperreach thereof so as to engage a slab in a tangential fashion to remove 6 bark therefrom, said tool also being curved in a trans verse direction relative to said conveyor to have a concave lower edge for conforming engagement with the upper curved surface of a slab.

No references cited.

UNITED STATES PATENT oFFicE CEBTIFIQATE 0F (IQRREUMUN Patent No. 2,848,022 August 19, 1958 John L, Gyllenberg It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 55, for necesaery read necessary line 67, for "grip" read strip column 4, line 36, for "betwen" read between Signed and sealed this 18th day of November 1958 (SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSQN Commissioner of Patents Attesting Officer 

